Fuel-burner for steam-generators.



F.-I. DU PONT.

FUEL BURNER FOR STEAM GENERATORS.

APPLICATION FILED MAR. 3, I917.

Pdtented Jan. 7.1919.

WITNESS. 1 WM.

ATTUR/VEX FUEL-BURNERFOR STEAM-GENERATORS.

Specification of Letters Patent.

Patented Jan. '3, 1919.

Application filed March 3,1917. I Serial No. 152,190.

ence being had to the accompanying drawings, which form a part of thisspecification.

The object of my invention is to provide improved means for supplyingliquid fuel to a steam boiler and which will be particularly adapted tothe supplying of liquid fuel to the boiler of a steam drivenmotorvehicle. More specifically, my object is to utilize steam or compressedair, preferably steam from theboiler under normal working conditions, toboth .lift the fuel, atomize it and spray it, and at the same timeaspirate the required quantity of air into the firebox, and so arrangedthat upon the cutting off of the steam the flow of fuel willautomatically stop. A further specific object of the invention is toprovide means for regulating the pressure of the steam in the boiler.

Inthe embodiment of my invention herein described I so construct the jetthat the pressure required to insure its proper operation will be verymuch below the maximum pressure desired in the boiler and safely belowany unusually low pressure in the boiler arismg from any sudden use ofsteam. Between the boiler and the atomizing jet regulating means arearranged whereby a-constant pressure at the atomizing et, of a degreemost favorable to the working of the jet, will be maintainednotwithstanding slight variations in boiler pressure, and whereby, whenthe boiler pressure exceeds a predetermined maximum, the'flow of steamfrom the boiler to the atomizing jet will be shut off, thereby stoppingalso the supply of fuel. I

A further object of the invention is to provide means for securing asteady flow of fluid, under requisite pressure, to the atom i zing jetbefore steam is generated in the boiler.

A preferred embodiment of the invention- The steam "boiler a has withinits fire-box a grille work I) of refractory material to retain anduniformly distribute the heat, and. to insure complete combustion of thefuel before the burning gaseous mixture comes 1n contact with therelatively cool surface of the boiler. The floor of the firebox slopesdownward toward an opening 0 of known form within which projects thefront of the fuel injector.

The injector, one of several practicable forms of which is shown indetail in Fig. 2, with the delivery end enlarged for purposes ofclearness, comprises a tubular chamber (1 having a slightly outwardlyflaring opening, and a steam pipe 0 extending longitudinally through thechamber (1 and the somewhat tapered nozzle end of which extends partlywithin the mouth of the chamber (Z.

Somewhat below the fuel injector d e is a receptacle f containing liquidfuel, such as kerosene or gasolene,'having an inlet pipe 9 communicatingwith its bottom. -Within the receptacle f is a float h to Which'issecured the stem of a valve 11 which, when the float is at apredetermined level, shuts off the admission of liquid fuel. A pipe 7'connects the receptacle with the tube d.

It is important that the level offuel in the receptacle f shall bemaintained a sufficiently short height m below the level of the fuelinjector and that the latter shall operate to aspirate the requiredquantity of air into the fire-box. This is particularly true of steamdriven road vehicles, for which use my invention is more particularlyadaptof the steam jet in the conical opening of the tube d produces asufficient vacuum to lift the liquid fuel. This type of atomizingaspirating jet is not new per se, and I'do not wish to be limited toany. particular construction of jet, as other constructions are knownand practicable. It will also be understood that the pressure mostfavorable to the working, 0f the jet will vary with the constructionthereof.

In regulating the pressure at the atom zing jet and maintaining itconstant and in regulating the pressure of steam in the boiler, Iinterpose in the steam pipe connections between the boiler and the fuelinjector two pressure regulators, which will now be described.

The first regulator k nearest the boiler is controlled by the pressureof the steam behind it (that is, in the boiler) and serves to close thesteam connections and so stop the fuel spray when the pressure risesabove a predetermined maximum, say, for example, 600 pounds to thesquare inch. This regulator is shown in Fig. 3. It comprises a needlevalve m located at the junction of two sections of the steam pipe, adiaphragm a secured to the stem of the valve, a frame 0 sup porting thediaphragm and the valve seat, a steam chamber p back of the diaphragm,and an adjustable spring 1' set to resist a definite pressure of steam.A branch pipe s connects the pipe 6 (between the boiler and the valve)with the chamber p. When the pressure of steam exceeds a predeterminedmaximum, the valve m closes and shuts off the flow of steam to theatomizing jet, and this being done the fuel ceases to be delivered tothe fire-box.

The second regulator 17 may be identical in construction with theregulator is and is interposed in the pipe 6 between the pressureregulator k and the fuel injector. Its steam chamber is connected, by apipe at, with the section of pipe in front of the valve of regulator t,so that if the steam pressure efiective.

at the atomizer exceeds a predetermined maximum, say 50 pounds, thevalve of regu lator 25 will close until the pressure drops.

In order that pressure fluid may be supv plied to the atomizer whenthere is no steam in the boiler, as in starting the engine, I provide anair pump '0 connected, by a valved pipe w, with the boiler. The pump isoper ated until the air within the boiler is compressed to the degreerequired to insure, after the valve y on the (pipe 6 is opened, a steadyflow of compresse air to the fuel injector until, after ignition of thefuel, a sufficient head of steam is generated to Perform the samefunction.

Having now fully described my invention, what I desire to claim Patentis:

1. In a fuel burner for steam generators, the combination with theboiler and its firebox having an opening to admit, a spray of liquidfuel, of a steam pipe connected with and protect by Letters liquid fuel,of a steam pipe connected with the boiler, a source of liquid fuelsupply, an injector connected with the steam pipe and the fuel supplyand adapted, at a proper steam pressure to inject fuel into the fireboxand to cease to inject fuel When the steam pressure drops, and tworegulators interposed in the steam pipe, one adapted to maintain thesteam pressure at the injector substantially constant and substantiallybelow the steam pressure in the boiler and the other adapted to shut oifthe flow of steam, and'hence also the supply of fuel, when the pressureof steam in the boiler rises above predetermined maximum.

3. In a fuel burner for steam generators, the combination with theboiler and its firebox having an opening to admit a spray of izingaspirating injector opposite said opening and located above saidpredetermined level and connected with both pipes, and

means interposed in the steam pipe to'maintain the steam pressure at theinjector substantially constant and substantially below the steampressure in the boiler and to cut off the flow of steam from the boilerwhen the pressure in the latter rises above a predetermined maximum.

4. In a fuel burner for steam generators, the combination with theboiler and its firebox having an opening to admit a spray of liquidfuel, of a fuel supply pipe, a steam pipe connected with the boiler, afuel injector connected with both pipes, and two pressure regulatorsinterposed in said steam pipe, one adapted to maintain a constantpressure of steam in the injector notwithstanding variations in boilerpressure and the other adapted to out 011' the flow of steam from theboiler when the pressure therein rises above a predetermined maximum.

5. In a fuel burner for steam generators, the combination with theboiler and its firebox having an opening to admit a spray of liquidfuel, of a fuel suppl pipe, a steam pipe connected with the boi er, afuel injector connected with both pipes, and two pres sure regulatorsinterposed in said steam pipe, one comprising a valve in the steam pipeand a connection between the pressure face of the valve and theinjector, and the other comprising a valve in the steam pipe between thefirst valve and the boiler and a connection between the pressureface ofthe second valve and the boiler.

6. In a fuel burner for steam generators,

the combination with the boiler and its fireliquid fuel, of a liquidfuel container, means to supply liquid fuel to the container and toregulate the level of the fuel therein, a pipe leading therefrom, asteam pipe connected with the boiler, an atomizing aspirating injectorlocated opposite said opening above the predetermined level of theliquid fuel and connected with both pipes, and two A pressure regulatorsinterposed in the steam plpe, one comprising a valve in the steam pipeand a connection between the pressure face of the valve and theinjector, and the other comprising a valve in the steam pipe between thefirst valve and the boiler and a connection between the pressure face ofthe second valve and the boiler.

7. In a fuel burner for steam generators, the combination with theboiler and its firebox having an opening to admit a spray of liquidfuel, of a liquid fuel receptacle, a valve controlling the admission offuel to the receptacle, a float in the receptacle connected with thevalve and adapted to regulate the level of liquid fuel in thereceptacle, an exit pipe from said receptacle, a steam pipe connectedwith the boiler, an atomizing aspirating injector opposite said openingand located above said predetermined level and connected with bothpipes, and two pressure regulators interposed in the steam plpe, oneadapted to maintain a constant pressure of steam in the injectornotwithstanding variations in boiler pressure below a predeterminedmaximum and the other adapted to cut off the flow of steam from theboiler when the pressure therein arises above a predetermined maximum.

In testimony of which invention I have hereunto set my hand, atWilmington, Delaware, on this 28th day of February, 1917.

FRANCIS I. DU PONT.

